The Bute Energy/Green GEN Project Proposal

The following is taken from the Green GEN Towy Usk project website. It explains what the proposal is.

The Green GEN Towy Usk proposal is for a new 132kV (132,000- volt) double-circuit overhead line, supported on steel pylons, between a substation on the Nant Mithil Energy Park in the Radnor Forest area and a new substation, to be developed by National Grid, on the existing 400kV (400,000-volt) transmission line near Llandyfaelog, between Carmarthen and Pont Abraham.

When drawing up our plans, we compared the environmental, technical and cost implications of 11 potential connection options. Following this work, connecting the Nant Mithil Energy Park to the national grid in the Carmarthen area was determined to be the most appropriate solution to take forward for more detailed routeing studies and consultation.

The new 132kV overhead line will be carried on steel lattice pylons. We need to use steel pylons because there will be two circuits (three sets of wires on each side of the pylons), carrying more power than can be carried safely on a single line of wooden poles. Each pylon will have three arms on each side, and each arm will carry a set of wires – known as conductors.

The standard height for a 132kv pylon is 27m. The average distance between pylons, or ‘span length’, is approximately 250m. Exact pylon heights and span lengths can be increased or decreased depending on the terrain they cross, or obstacles like streams and rivers.

Working with our environmental consultants, we identified corridors of land through which an overhead line route could be installed, looking at how each might affect local communities, the landscape, local views, biodiversity, forestry and cultural heritage, floor risk and other land uses. 

We then selected a preferred corridor for Green GEN Towy Usk and identified potential route options within it. Following further research, we have selected a preferred route in that corridor to take forward for public consultation. Our preferred route avoids and seeks to reduce potential impacts on the Brecon Beacons National Park and other sensitive landscapes, and required the least amount of new infrastructure.

We believe this route achieves the best balance between our technical requirements and minimising the impact on the environment and the people, who live, work and enjoy spending their time in the area.

We know that new infrastructure can be disruptive to communities. We are committed to doing everything we can to cause the least disturbance to the environment and those who live, work and enjoy recreation close to our proposals.

You can find out more information about how we identified our preferred route, and the other options we considered, in our Routeing and Consultation Document and our Grid Connection Strategy Report. 


Click here for interactive map (opens in Green GEN Towy-Usk website)

photo from In Your Area


The entire concept of relying on overground cables using pylons is flawed. If such a link is needed, then there is a strong consensus that the cables should be routed underground, regardless of the additional cost. However, the best option for the country to meet its Net Zero targets would be to locate the green energy source nearer to its potential grid connection site.

This is not a project ‘for Wales’ and should not be presented as such. The Green GEN Cymru/Bute Energy literature justifying the pylon line from Nant Mithil to Llandyfaelog, suggests that this is a green project for Wales. However, the electricity generated would be fed into the UK National Grid so it is not a case of the energy being produced in Wales for the benefit of Wales. Wales already generates approximately twice as much electricity as it consumes.

So, we say NO to the Green GEN Cymru/Bute Energy proposals and ask others to join us in our fight to stop our countryside from being blighted and irreversibly damaged.